I have an issue with Nifi v1.6 i was trying to write small python script inside ExecuteScript processor :Although i was just calling session.read with Callback function: the error is org.apache.nifi.processor.exception.ProcessException: javax.script.ScriptException: java.lang.IllegalStateException: java.lang.IllegalStateException: StandardFlowFileRecord[uuid=1343dc70-6750-4269-af88-d02784c07a44,claim=StandardContentClaim [resourceClaim=StandardResourceClaim[id=1533643252945-1, container=default, section=1], offset=675, length=61],offset=0,name=21873824285366087,size=61] already in use for an active callback or an InputStream created by ProcessSession.read(FlowFile) has not been closed in <script> at line number Code as follows from org.apache.nifi.processors.script import ExecuteScript from org.apache.commons.io import IOUtils from java.nio.charset import StandardCharsets from org.apache.nifi.processor.io import InputStreamCallback import sys, re import traceback from org.python.core.util import StringUtil class SplitCallback(InputStreamCallback): def __init__(self): self.parentFlowFile = None def process(self, inputStream): try: input_text = IOUtils.toString(inputStream, StandardCharsets.UTF_8) input_list = input_text.split('\n') # Create FlowFiles for array items splits = [] splitFlowFile = session.create(self.parentFlowFile) for record in input_list: words = record.split(" ") if words[1].lower() == "running" : continue else: splitFlowFile = session.putAllAttributes(splitFlowFile, {'Application': words[0],'Status': words[1]}) splits.append(splitFlowFile) if len(splits) > 0 : for splitFlowFile in splits: session.transfer(splitFlowFile, ExecuteScript.REL_FAILURE) else: session.transfer(splitFlowFile, ExecuteScript.REL_SUCCESS) except: traceback.print_exc(file=sys.stdout) raise finally: if inputStream is not None : inputStream.close() session.commit() parentFlowFile = session.get() if parentFlowFile != None: splitCallback = SplitCallback() splitCallback.parentFlowFile = parentFlowFile session.read(parentFlowFile,splitCallback) ... View more